Mobile working machines like mobile boom cranes, man lifts, self-propelled concrete mixers are typically not supported relative to a ground surface through their suspensions during operations but are supported by lateral outriggers which are laterally extendable and/or pivotable from the chassis and include support bases that are extendable in downward direction at their free ends. This way, the suspension springs of the vehicle are rendered non-functional and the support surface can be considerably enlarged relative to the suspension and thus the working machine can be stabilized better or improved operating parameters like maximum extension, maximum crane load, etc. can be achieved. A working machine that is not supported correctly can tip over.
Therefore it is already known to safely monitor reaching the extended end position of the telescoping lateral outriggers, either through manually locking the telescoping outrigger arm in an end position through a bolt or automatically in that a sensor indicates reaching the end position of the telescoping rigger arm.
Typically, however, a mobile working machine of this type has to be used under restricting environmental conditions so that the outriggers cannot be extended to the full length in these locations, but can only be extended to an intermediary position which then cause reduced operating parameters of the machine.
With this respect, it is already known to detect predefined intermediary positions of the extension length of the lateral outrigger through particular sensors.
Furthermore, it is known from EP 1 77 2415 A2 to continuously detect the extension length of lateral outriggers through an optical distance measuring system between two profiles of the lateral outrigger that are configured to be telescopable relative to one another.
Therein, the choice of an optical distance measuring device is based on the fact that inductive or magnetic induction sensors cause limitations in the material choice in the environment of the sensor.
Lateral outriggers of this type as illustrated supra can be telescopable and can be moved into a transport position at the vehicle through retracting the telescope from the operating position.
Another option to approach a transport position is folding the lateral outriggers laterally towards the chassis of the vehicle about a vertical pivot axis.
This has the additional advantage that the laterally extended lateral outriggers do not have to protrude precisely at a right angle to the driving direction of the vehicle in operating position, but are adjustable with respect to their angular position which is advantageous for obstacles in the environment of the operating machine.
Pivoting the lateral outriggers about a vertical axis and telescoping the lateral outriggers can also be implemented in a combined manner at a lateral outrigger.